拋出dubbo中的異常

以maven子模塊的方式搭建

<groupId>cn.theviper</groupId>
    <artifactId>dubbo-exception</artifactId>
    <packaging>pom</packaging>
    <version>1.0</version>

    <modules>
        <module>api</module>
        <module>server</module>
    </modules>

api部分

public class APIException extends RuntimeException implements Serializable{

    public int code;
    public String msg;

    public APIException(String msg) {
        super(msg);
    }

    public APIException(int code, String msg) {
        super(msg);
        this.code = code;
        this.msg = msg;
    }
    ...
}

一般咱們會定義一系列業務錯誤碼

public enum APICode {

    OK(Integer.valueOf(0), "success"),
    PARAM_INVALID(4100, "parameter invalid");

    private int code;
    private String msg;

    APICode(int code, String msg) {
        this.code = code;
        this.msg = msg;
    }

    getter setter...

}

錯誤碼是放在server仍是api好呢?
固然是放在server好呢,由於不用每次一修改業務錯誤碼,就要更新api版本,可是api又不能反過來依賴server,怎麼辦呢?

spring aop

spring aop加強裏面有一個拋出異常加強,用它來轉發一下code和msg就好了

• server加入依賴

<dependencies>
    <dependency>
        <groupId>org.aspectj</groupId>
        <artifactId>aspectjweaver</artifactId>
        <version>1.8.9</version>
    </dependency>
</dependencies>

• server定義切面

@Component
@Aspect
public class ServiceExceptionInterceptor {

    private static final Logger logger = LoggerFactory.getLogger(ServiceExceptionInterceptor.class);

    @AfterThrowing(throwing="ex",pointcut="execution(* cn.theviper.service.**.*(..))")
    public APIResult handle(ServiceException ex){
        logger.info("intercept ServiceException:{}",ex.toString());
        throw new APIException(ex.getCode(),ex.getMsg());
    }

}

• spring配置

<aop:aspectj-autoproxy/>

能夠看到,切面就是攔截了ServiceException,把ServiceException裏面的code,msg又傳給APIException了

返回的結果

錯誤碼放在server帶來一個新的問題,api的返回結果每每會用到這個錯誤碼,怎麼辦呢?
用繼承就行了

• api

APIResult register(RegisterForm form) throws APIException;

public class APIResult<T> implements Serializable{

    public int code;
    public T data;
    public String msg;

    public APIResult() {
    }
    ...

}

• server

public class ServerResult<T> extends APIResult<T>{

    public ServerResult() {
    }

    public ServerResult(APICode apiCode){
        this.code=apiCode.getCode();
        this.msg=apiCode.getMsg();
    }

    public ServerResult setData(T data){
        super.data=data;
        return this;
    }

}

返回的時候,直接

return new ServerResult(APICode.OK).setData("callback msg");

關於dubbo的異常分析,能夠參見淺談dubbo的ExceptionFilter異常處理

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